One of the overall objectives is to continue the project of making ultrasound anthropomorphic breast phantoms for use in testing state-of-the-art ultrasonic imaging machines and for use in training ultrasonographers and clinicians in ultrasonic breast imaging. The breast phantoms produced so far mimic the various breast tissue parenchyma quantitatively in terms of attenuation, speed of sound and density and qualitatively in terms of scatter--qualitatively because only small particle scatter has been available in our materials up to now. A new method for controlled mass production of spheres of our heretofore tissue-mimicking materials in the intermediate and large particle range has been developed. This new capacity will allow us, by making scatter measurements and comparing to corresponding measurements on breast tissues, to mimic the various breast tissue parenchymal quantitatively in terms of scatter. We will subsequently pursue detailed mimicking of the ultrasonic characteristics of masses of various kinds (tumors, cysts, calcifications). Histological and radiographic studies along with interaction with clinicians regarding the ultrasonic appearance of these masses will contribute significantly to this effort. Our expertise regarding molding and attachment of stimulated tumor spicules gives us considerable latitude in this area. We will then turn our attention to the production of sets of phantoms for comparing the imaging and diagnostic capabilities of ultrasound with those of x-rays. The materials used to mimic the various tissues ultrasonically can be made simultaneously x-ray tissue-equivalent. A further study of material properties along with studies of tumor density and chemical composition will be needed. Another important overall objective will be to use our expertise producing breast phantoms to make a study of the nature of ultrasound beam distortions and B-scan texture patterns as functions of the phantom detailed structure and the nature of the imaging system. Such a study could lead to statements regarding optimization of transducer parameters and regarding diagnostic implications of texture patterns.